Polymer and organic solar cell comprising same

Abstract

The present specification relates to a polymer and an organic solar cell including the same.

What is claimed is: 
     
       1. A polymer comprising:
 a first unit of Chemical Formula 1; and 
 a second unit of Chemical Formula 2: 
 
       
         
           
           
               
               
           
         
         wherein: 
         d1, d2, x, and x′ are each 1 or 2; 
         when d1, d2, x, and x′ are each 2, structures in the parenthesis are the same as or different from each other; 
         X1 and X2 are the same as or different from each other, and are each independently CRR′, NR, O, SiRR′, PR, S, GeRR′, Se or Te; 
         Y1 to Y4 are the same as or different from each other, and are each independently CR″, N, SiR″, P, or GeR″; 
         X and X′ are the same as or different from each other, and are each independently S or Se; 
         Ar1 and Ar2 are the same as or different from each other, and are each independently a substituted or unsubstituted straight or branched alkyl group; 
         R1 and R2 are the same as or different from each other, and are each independently a substituted or unsubstituted branched alkyl group; 
         G1 and G2 are the same as or different from each other, and are each independently hydrogen, or fluorine; 
         R, R′, and R″ are the same as or different from each other, and are each independently hydrogen, deuterium, a halogen group, a hydroxy group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic group; and 
         D1 and D2 are the same as or different from each other, and are each independently any one selected from the following structures, 
       
       
         
           
           
               
               
           
         
         wherein: 
         X″, X′″, and X″″ are the same as or different from each other, and are each independently S or Se; 
         Y and Y′ are the same as or different from each other, and are each independently CR′″, N, SiR′″, P, or Ge R′″; 
         G11 to G18, G101, and G102 are the same as or different from each other, and are each independently hydrogen, or fluorine; 
         R′″ is hydrogen, deuterium, a halogen group, a hydroxy group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic group; and 
         g is 0 or 1. 
       
     
     
       2. The polymer of  claim 1 , wherein Chemical Formula 1 is Chemical Formula 1-1: 
       
         
           
           
               
               
           
         
         wherein Ar1, Ar2, and D1 are the same as those defined in Chemical Formula 1. 
       
     
     
       3. The polymer of  claim 1 , wherein Chemical Formula 2 is Chemical Formula 2-1: 
       
         
           
           
               
               
           
         
         wherein R1, R2, G1, G2, and D2 are the same as those defined in Chemical Formula 2. 
       
     
     
       4. The polymer of  claim 1 , wherein Chemical Formula 1 is any one of Chemical Formulae 1-2 to 1-5: 
       
         
           
           
               
               
           
         
         wherein: 
         Ar1 and Ar2 are the same as those defined in Chemical Formula 1; 
         G11 to G18, G101, and G102 are the same as or different from each other, and are each independently hydrogen, or fluorine; and 
         R′″ is hydrogen, deuterium, a halogen group, a hydroxy group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic group. 
       
     
     
       5. The polymer of  claim 1 , wherein Chemical Formula 2 is any one of Chemical Formulae 2-2 to 2-5: 
       
         
           
           
               
               
           
         
         wherein: 
         R1, R2, G1, and G2 are the same as those defined in Chemical Formula 2; 
         G11 to G18, G101, and G102 are the same as or different from each other, and are each independently hydrogen, or fluorine; and 
         R′″ is hydrogen, deuterium, a halogen group, a hydroxy group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic group. 
       
     
     
       6. The polymer of  claim 1 , wherein the polymer comprises a unit of Chemical Formula 4 or 5: 
       
         
           
           
               
               
           
         
         wherein: 
         A is Chemical Formula 1; 
         B is Chemical Formula 2; 
         l is a mole fraction and 0<l<1; 
         m is a mole fraction and 0<m<1; 
         l+m=1; and 
         n is a repeating number of the unit, and is an integer of from 1 to 10,000. 
       
     
     
       7. The polymer of  claim 1 , wherein the polymer comprises a unit of any one of Chemical Formulae 4-1 to 4-16 and 5-1 to 5-16: 
       
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         wherein: 
         Ar1 and Ar2 are the same as those defined in Chemical Formula 1; 
         R1, R2, G1, and G2 are the same as those defined in Chemical Formula 2; 
         G11 to G18, G101, and G102 are the same as or different from each other, and are each independently hydrogen, or fluorine; 
         R′″ is hydrogen, deuterium, a halogen group, a hydroxy group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic group; 
         l is a mole fraction and 0<l<1; 
         m is a mole fraction and 0<m<1; 
         l+m=1; and 
         n is a repeating number of the unit, and is an integer of from 1 to 10,000. 
       
     
     
       8. The polymer of  claim 1 , wherein the polymer comprises a unit of any one of Chemical Formulae 5-1-1, 5-5-1, 5-11-1, and 5-16-1: 
       
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         wherein: 
         l is a mole fraction and 0<l<1; 
         m is a mole fraction and 0<m<1; 
         l+m=1; and 
         n is a repeating number of the unit, and is an integer of from 1 to 10,000. 
       
     
     
       9. The polymer of  claim 1 , wherein the polymer has a HOMO energy level of 5 eV to 5.9 eV. 
     
     
       10. The polymer of  claim 1 , wherein the polymer has a number average molecular weight of 5,000 g/mol to 1,000,000 g/mol. 
     
     
       11. The polymer of  claim 1 , wherein the polymer has a molecular weight distribution of 1 to 10. 
     
     
       12. An organic solar cell comprising:
 a first electrode; 
 a second electrode facing the first electrode; and 
 an organic material layer between the first electrode and the second electrode, the organic material layer comprising one or more layers and comprising a photoactive layer, 
 wherein the one or more layers of the organic material layer comprise the polymer of  claim 1 . 
 
     
     
       13. The organic solar cell of  claim 12 , wherein the photoactive layer comprises one or more selected from the group consisting of an electron donor and an electron acceptor, and
 wherein the electron donor comprises the polymer of  claim 1 . 
 
     
     
       14. The organic solar cell of  claim 13 , wherein the electron donor and the electron acceptor are both present and constitute a bulk heterojunction (BHJ). 
     
     
       15. The organic solar cell of  claim 13 , wherein the photoactive layer further comprises an additive. 
     
     
       16. The organic solar cell of  claim 12 , wherein the photoactive layer has a bilayer thin film structure comprising an n-type organic material layer and a p-type organic material layer, and
 wherein the p-type organic material layer comprises the polymer of  claim 1 . 
 
     
     
       17. The organic solar cell of  claim 15 , wherein the additive comprises one or two additives selected from the group consisting of 1,8-diiodooctane (DIO), 1-chloronaphthalene (1-CN), diphenylether (DPE), octane dithiol, and tetrabromothiophene. 
     
     
       18. The organic solar cell of  claim 15 , wherein the additive comprises an organic material having a boiling point of 30° C. to 300° C. 
     
     
       19. The polymer of  claim 1 , wherein the polymer has a number average molecular weight of 100,000 g/mol or less. 
     
     
       20. The polymer of  claim 1 , wherein the polymer has a molecular weight distribution of 1 to 3.